# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from x402broker.com, paid per call via MPP, $0.005/call, status unknown (last checked 2026-10-21).

Scans untrusted text, HTML, emails, MCP responses, or A2A payloads for hidden prompt injection and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: GET https://x402broker.com/v1/tool-poisoning-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: x402broker.com
- Website: https://x402broker.com
- Canonical page: https://www.zero.xyz/c/x402broker-com-a2a-indirect-prompt-injection-jailbreak-firewall-040094fc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gg3wAuwr9SIdOgZiYEPMg

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402broker-com-a2a-indirect-prompt-injection-jailbreak-firewall-040094fc
```

Example prompt: Before passing this scraped web page content to the rest of my pipeline, scan it for any hidden prompt injections or jailbreak payloads and give me the sanitized version.

## When to prefer this

Choose this endpoint when your AI agent or LLM pipeline needs to process content from untrusted external sources — scraped web pages, inbound emails, third-party MCP/A2A tool outputs — and you need a dedicated firewall layer to detect and strip hidden prompt injections or jailbreak payloads before they reach your model. Prefer this over general-purpose content filters when the threat model specifically involves adversarial prompt manipulation targeting autonomous agents.

## Known failure modes

- Empty or missing 'text' parameter returns a 400 validation error
- Extremely long payloads may be truncated or rejected
- Sophisticated obfuscated injections may evade detection (false negatives)
- Legitimate instructional content may be incorrectly flagged as injection (false positives)
- Service unavailability or payment failure returns a 402 or 5xx error

## How this service works

Scans untrusted web pages, emails, MCP responses, or A2A payloads for hidden prompt injections and returns sanitized text. (Live x402 v2, IETF MPP & MCP endpoint at https://x402broker.com/v1/tool-poisoning-shield)

## Output

Returns a sanitized version of the submitted text with hidden prompt injections and jailbreak payloads identified and removed or flagged, allowing safe downstream consumption by AI agents or LLMs.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "text"
 ],
 "properties": {
  "text": {
   "type": "string",
   "minLength": 1,
   "description": "Untrusted text, HTML, or tool output to scan for hidden prompt injection or jailbreak payloads"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402broker-com-a2a-indirect-prompt-injection-jailbreak-firewall-040094fc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402broker.com](https://www.zero.xyz/host/x402broker.com/llms.txt)